1. Field of the Invention
The present invention relates to a production method of a mold, a manufacturing method of a pattern sheet, a production method of an electroform, a production method of a mold using an electroform, and an original.
2. Description of the Related Art
In recent years, as a novel dosage form capable of injecting drugs such as insulin, vaccines, and human growth hormone (hGH) into the skin without pain, a microneedle array has been known. The microneedle array is an array of microneedles (also referred to as fine needles or small needles) which contain drugs and are biodegradable. By attaching this microneedle array to the skin, each microneedle pierces the skin, these microneedles are absorbed in the skin such that the drugs contained in each microneedle can be administered into the skin. Microneedle arrays are also called percutaneous absorption sheets.
In order to produce a formed product having a fine protruding pattern like the microneedle array as described above, a resin mold having the inverted shape is formed from an original having a fine protruding pattern, and a formed product is produced from the mold. There is a demand for improving the productivity of formed products having fine patterns, and various proposals have been made.
JP2007-535343A discloses a production method of a mold base for manufacturing microneedles. In the technique described in JP2007-535343A, a mold base for manufacturing microneedles is produced by pressing a master model having master model needle arrays against a mold plate for manufacturing microneedles, and a formed product having a fine pattern is produced by using the mold base for manufacturing microneedles.
JP2011-083993A discloses transferring a transfer pattern formed on a mold to a plurality of points of a thermoplastic resin. In the technique described in JP2011-083993A, a heated mold is pressed against a thermoplastic resin and is cooled, and the mold is separated from the thermoplastic resin, thereby transferring the transfer pattern of the mold to the thermoplastic resin. Furthermore, moving the heated mold, pressing the mold against the thermoplastic resin and cooling the mold, and separating the mold from the thermoplastic resin are repeated, thereby transferring the transfer pattern of the mold to the thermoplastic resin.